I've just installed Linux Mint 13, 64 bit (from the CD of "c't kompakt Linux", if this matters), and came across a very unexpected problem, for which I've not found a solution with Google or searching this site: It claims that my LAN cable were not connected. This is surprising because both the live version of Linux Mint (from which I installed it) and the OpenSUSE running on the same computer (on which I'm currently typing this) are connecting quite fine over the very same network cable (which I didn't touch in the mean time).

So what could have gone wrong? And more importantly, what can I do to fix it?

Update:

After switching off the computer and disconnecting it from power (due to a thunderstorm), after booting up again it now works. Anyway, if someone has an idea what it might have been (I've not touched the LAN cable at all!), I'd still appreciate to know (in case it happens again).